Low-energy input buzzer

ABSTRACT

A vibratory buzzer device having a relatively thin-gage metal, cup-shaped cover or housing which acts as a sounding surface when struck by a electromagnetically actuated vibrating reed which strikes the cover through a hard, electrically insulating hammer element, the cover thus being electrically insulated from the buzzer circuit.

United States Patent Bayamon, P.R.

Appl. No. Filed Patented Assignee LOW-ENERGY INPUT BUZZER [5 6]References Cited UNITED STATES PATENTS 509,050 11/1893 Schweiger 340/3963,425,057 H1969 Doggart 340/396 3,540,039 ll/l970 McCarty 340/402Primary ExaminerThomas B. Habecker Attorney- Woodard, Weikart, Emhardt &Naughton ABSTRACT: A vibratory buzzer device having a relativelythin-gage metal, cup-shaped cover or housing which acts as a soundingsurface when struck by a electromagnetically actuated vibrating reedwhich strikes the cover through a hard, electrically insulating hammerelement, the cover thus being electrically insulated from the buzzercircuit.

4 Claims, 4 Drawing Figs.

U.S. Cl 340/396, 340/402 Int. Cl G08b 3/00 Field of Search 340/396, 402,392

BACKGROUND OF THE INVENTION Audial signalling devices have been utilizedin many and various applications. Their use in conjunction with turnsignal apparatus, mandatory on motor vehicles, has made important theprovision of low-cost, low-energy input vibratory mechanism which willhave a long operating life and a relatively high sound output.

The present invention fulfills these requirements by utilizing anelectromagnetically actuated, vibrating reed carrying an electricallyinsulating striker which engages the cup-shaped thin metal housing coverfor the apparatus, consequent vibration of the cover itself producingthe desired audial signal.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side sectional view of theapparatus embodying the present invention.

FIG. 2 is a top plan view of the apparatus shown in FIG. I with thecup-shaped cover removed.

FIG. 3 is a top plan view of the vibrating reed component of theapparatus.

FIG. 4 is a schematic illustration of the electrical circuit of theapparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, theapparatus includes a circular, rigid baseplate 10, formed of a suitableelectrical insulating material. Covering the upper face of the baseplateis a cupshaped cover 11, preferably formed of thin-gauge metal, which issecured or clamped only at its circular margin 12 to the peripheralportion of the baseplate 10. A bifurcated chassis member 13 is formed toprovide a central, extending leg 14 and two downwardly flanged mountinglegs 16 and 17 which are riveted to the baseplate 10.

The end of the chassis member identified at 17 is upwardly flanged andhas secured to it a reed 21, shown in detail in FIG. 3 and formed of aresilient metal. The reed 21 and the portion 17 of the chassis are inelectrically conducting relation, being clamped therein by the enclosingclamp portion 22 of the rigid metal arm 23 which carries a stationaryelectrical contact 24 at its free end. An electrical insulating wrap 26permits the portion 22 to clamp the reed and chassis without providingelectrical continuity to the arm 23 and its contact 24.

Intermediate its ends the reed 21 carries an electrical contact 27 whichis adapted to cooperate with the stationary contact 24. At its free endthe reed carries an armature weight 28 and, extending upwardly from theweight 28 is an abutment formed by a glass bead 31. The bead 31functions as a striker engaging the inner face of the concavo-convexdepression 32 in the center of the cover 11. The reed 21 is providedwith a struck-out portion or notch 21a adjacent its fixed end, the slotserving to facilitate flexibility of the reed permitting it to vibrateat a lower voltage placed on the coil which induces its vibratory motionas will subsequently be described.

The central extending leg 14 of the chassis has mounted thereon anelectrical coil 34, the central, terminal portion of the leg 14 actingas the electromagnetic core for the coil and permitting flux linkage ofthe core and the armature weight 28 when the coil is electricallyenergized. Extending from the outer face of the baseplate 10, andattached thereto by suitable tabs are electrical terminal members 36 and37 (FIG. 2). As will be evident from FIG. 2, a wire 35 connects theterminal 36 to the arm 23 and its contact 24. A wire 38 (FIG. 1)

connects one end of the coil 34 to the chassis and a wire 41 connectsthe other end of the coil to the terminal 37. The electrical circuitthus provided is shown schematically in FIG. 4.

In operation, when the starting voltage is placed across the terminals36 and 37, energization of coil 34 will serve to deflect the reed 21downwardly, breaking or separating the contacts 24 and 27. As will beevident from FIG. 4, separating of contacts 24 and 27 breaks the circuitthrough the coil 34,

deenergizjng it, and releasing the armature 28 and the reed to which itis attached. The consequent rebound movement of the reed upwardly causesthe abutment 31 to strike the cover portion 32 and the vibratoryrepeating of this cycle causes a corresponding vibration of the coverproducing a loud, audible signal.

The buzzer apparatus described has a prolonged operating life and arelatively high sound output. The thin, cup-shaped cover is clamped orsecured only at its marginal edges leaving the remainder of the coverfree to vibrate in accord with the frequency of the blows delivered toit by the abutment 31. The cover itself acts as the sound cone or anvilthus eliminating that component of conventional structures. The thin,slotted reed with the weight 28 at its free end produces the requiredsound with a minimum expenditure of energy since only the internalfriction in the reed must be overcome by the electromagnetic forcegenerated by the coil 34. A relatively small wire coil may thus be usedthereby reducing material cost and reducing the heat generated by thestructure in operation and thereby permitting the apparatus to becontinuously operated. The cover must be electrically dead, that is,electrically insulated from the circuit through the contacts and coil.The glass bead, because it is hard and is electrically insulating,provides the type of striker necessary to achieve these advantages.

1 claim:

1. An electromagnetically actuated, low-energy audio signalling devicecomprising a rigid baseplate having electrical terminals extendingthrough the plate and from one face thereof, a cup-shaped cover securedonly at its margin to said baseplate and overlying the other face of theplate, a flexible reed cantilever mounted within said cover andsupported from said baseplate, the free end of said reed carryingweighted striker adapted to strike said cover when the reed is flexed,an electrical contact carried by said reed intermediate its length andadapted to cooperate with an adjacent fixed contact to control anelectrical circuit between said electrical terminals, an electromagneticcoil supported from the baseplate adjacent said reed and electricallyconnected in series with said contacts, the flux linkage of said coiland reed when the coil is energized serving to flex said reed away fromsaid cover and opening said contacts, the rebound of said reed toreclose said contacts then causing the reed to flex toward said coverand said striker to strike said cover, the cyclical flexing of the reedand striking of the cover thereby causing said cover to correspondinglyvibrate producing an audial signal.

2. An audio signalling device as claimed in claim 1 in which the portionof said weighted striker which engages said cover is formed by anelectrically insulating glass bead.

3. An audio signalling device as claimed in claim 2 in which a centralindentation is formed in said cup-shaped cover to define the area of thecover adapted to be engaged on the convex side of the indentation bysaid glass head portion of said weighted striker.

4. An audio signalling device as claimed in claim 3 in which saidflexible reed is slotted intermediate its ends to reduce the forcenecessary to flex said reed.

1. An electromagnetically actuated, low-energy audio signalling devicecomprising a rigid baseplate having electrical terminals extendingthrough the plate and from one face thereof, a cupshaped cover securedonly at its margin to said baseplate and overlying the other face of theplate, a flexible reed cantilever mounted within said cover andsupported from said baseplate, the free end of said reed carryingweighted striker adapted to strike said cover when the reed is flexed,an electrical contact carried by said reed intermediate its length andadapted to cooperate with an adjacent fixed contact to control anelectrical circuit between said electrical terminals, an electromagneticcoil supported from the baseplate adjacent said reed and electricallyconnected in series with said contacts, the flux linkage of said coiland reed when the coil is energized serving to flex said reed away fromsaid cover and opening said contacts, the rebound of said reed toreclose said contacts then causing the reed to flex toward said coverand said striker to strike said cover, the cyclical flexing of the reedand striking of the cover thereby causing said cover to correspondinglyvibrate producing an audial signal.
 2. An audio signalling device asclaimed in claim 1 in which the portion of said weighted striker whichengages said cover is formed by an electrically insulating glass bead.3. An audio signalling device as claimed in claim 2 in which a centralindentation is formed in said cup-shaped cover to define the area of thecover adapted to be engaged on the convex side of the indentation bysaid glass bead portion of said weighted striker.
 4. An audio signallingdevice as claimed in claim 3 in which said flexible reed is slottedintermediate its ends to reduce the force necessary to flex said reed.